The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.
Nuclear power plants require emergency systems for providing ‘clean air’ to plant control room habitability areas (CRHAs) in the case of a radiological and/or toxic event, i.e., the accidental release or leakage of radioactive and/or toxic contaminates, gas or smoke. Typically pressurized air storage systems are implemented to provide clean, safe air, i.e., air free of radioactive and toxic contaminates, for main control room emergency habitability in such situations. Such known pressurized air storage systems require the storage of large pressurized air tanks and the installation of associated piping, tubing, valves, regulator, instrumentation and operational controls. Additionally, systems and equipment must be installed to avoid over-pressurization during operation of such known pressurized air storage systems. Thus, known pressurized air storage systems can be design problematic, expensive to install, implement and operate, and problematic to maintain.
Furthermore, known control room habitability area HVAC subsystem designs typically utilize standard commercial draw through type air handling units (AHU) to circulate and condition air, i.e., heat and cool air, within the CRHA. More particularly, the layout of such designs typically requires one or more AHUs and return/exhaust fans to be installed externally to the CRHA. For example, often one or more AHUs and return/exhaust fans are located in a mechanical equipment room that is separated from the CRHA. The utilization of external AHUs and fans necessitates the installation of a large amount of insulated ductwork that must be routed from outside the CRHA to the interior of the CRHA. Such routing of ductwork from outside the CRHA can be problematic in meeting safety requirements regarding the ‘in-leakage’ of radioactive contaminated air from outside the CRHA during a radiological and/or toxic event.